polygerrit-ui/app/utils/comment-util.ts - gerrit - Git at Google

 /**
  * @license
  * Copyright 2020 Google LLC
  * SPDX-License-Identifier: Apache-2.0
  */
 import {
   CommentBasics,
   CommentInfo,
   PatchSetNum,
   RobotCommentInfo,
   Timestamp,
   UrlEncodedCommentId,
   CommentRange,
   PatchRange,
   PARENT,
   ContextLine,
   BasePatchSetNum,
   RevisionPatchSetNum,
   AccountInfo,
   AccountDetailInfo,
   ChangeMessageInfo,
   VotingRangeInfo,
   FixSuggestionInfo,
   FixId,
   PatchSetNumber,
 } from '../types/common';
 import {CommentSide, SpecialFilePath} from '../constants/constants';
 import {parseDate} from './date-util';
 import {CommentIdToCommentThreadMap} from '../elements/diff/gr-comment-api/gr-comment-api';
 import {isMergeParent, getParentIndex} from './patch-set-util';
 import {DiffInfo} from '../types/diff';
 import {LineNumber} from '../api/diff';
 import {FormattedReviewerUpdateInfo} from '../types/types';
 import {extractMentionedUsers} from './account-util';

 export interface DraftCommentProps {
   // This must be true for all drafts. Drafts received from the backend will be
   // modified immediately with __draft:true before allowing them to get into
   // the application state.
   __draft: boolean;
 }

 export interface UnsavedCommentProps {
   // This must be true for all unsaved comment drafts. An unsaved draft is
   // always just local to a comment component like <gr-comment> or
   // <gr-comment-thread>. Unsaved drafts will never appear in the application
   // state.
   __unsaved: boolean;
 }

 export type DraftInfo = CommentInfo & DraftCommentProps;

 export type UnsavedInfo = CommentBasics & UnsavedCommentProps;

 export type Comment = UnsavedInfo | DraftInfo | CommentInfo | RobotCommentInfo;

 // TODO: Replace the CommentMap type with just an array of paths.
 export type CommentMap = {[path: string]: boolean};

 export function isRobot<T extends CommentBasics>(
   x: T | DraftInfo | RobotCommentInfo | undefined
 ): x is RobotCommentInfo {
   return !!x && !!(x as RobotCommentInfo).robot_id;
 }

 export function isDraft<T extends CommentBasics>(
   x: T | DraftInfo | undefined
 ): x is DraftInfo {
   return !!x && !!(x as DraftInfo).__draft;
 }

 export function isUnsaved<T extends CommentBasics>(
   x: T | UnsavedInfo | undefined
 ): x is UnsavedInfo {
   return !!x && !!(x as UnsavedInfo).__unsaved;
 }

 export function isDraftOrUnsaved<T extends CommentBasics>(
   x: T | DraftInfo | UnsavedInfo | undefined
 ): x is UnsavedInfo | DraftInfo {
   return isDraft(x) || isUnsaved(x);
 }

 interface SortableComment {
   updated: Timestamp;
   id: UrlEncodedCommentId;
 }

 export interface ChangeMessage extends ChangeMessageInfo {
   // TODO(TS): maybe should be an enum instead
   type: string;
   expanded: boolean;
   commentThreads: CommentThread[];
 }

 export function isFormattedReviewerUpdate(
   message: ChangeMessage
 ): message is ChangeMessage & FormattedReviewerUpdateInfo {
   return message.type === 'REVIEWER_UPDATE';
 }

 export type LabelExtreme = {[labelName: string]: VotingRangeInfo};

 export const NEWLINE_PATTERN = /\n/g;

 export const PATCH_SET_PREFIX_PATTERN =
   /^(?:Uploaded\s*)?[Pp]atch [Ss]et \d+:\s*(.*)/;

 export function sortComments<T extends SortableComment>(comments: T[]): T[] {
   return comments.slice(0).sort((c1, c2) => {
     const d1 = isDraft(c1);
     const d2 = isDraft(c2);
     if (d1 !== d2) return d1 ? 1 : -1;

     const date1 = parseDate(c1.updated);
     const date2 = parseDate(c2.updated);
     const dateDiff = date1.valueOf() - date2.valueOf();
     if (dateDiff !== 0) return dateDiff;

     const id1 = c1.id;
     const id2 = c2.id;
     return id1.localeCompare(id2);
   });
 }

 export function createUnsavedComment(thread: CommentThread): UnsavedInfo {
   return {
     path: thread.path,
     patch_set: thread.patchNum,
     side: thread.commentSide ?? CommentSide.REVISION,
     line: typeof thread.line === 'number' ? thread.line : undefined,
     range: thread.range,
     parent: thread.mergeParentNum,
     message: '',
     unresolved: true,
     __unsaved: true,
   };
 }

 export function createPatchsetLevelUnsavedDraft(
   patchNum?: PatchSetNumber,
   message?: string,
   unresolved?: boolean
 ): UnsavedInfo {
   return {
     patch_set: patchNum,
     message,
     unresolved,
     path: SpecialFilePath.PATCHSET_LEVEL_COMMENTS,
     __unsaved: true,
   };
 }

 export function createUnsavedReply(
   replyingTo: CommentInfo,
   message: string,
   unresolved: boolean
 ): UnsavedInfo {
   return {
     path: replyingTo.path,
     patch_set: replyingTo.patch_set,
     side: replyingTo.side,
     line: replyingTo.line,
     range: replyingTo.range,
     parent: replyingTo.parent,
     in_reply_to: replyingTo.id,
     message,
     unresolved,
     __unsaved: true,
   };
 }

 export function createCommentThreads(comments: CommentInfo[]) {
   const sortedComments = sortComments(comments);
   const threads: CommentThread[] = [];
   const idThreadMap: CommentIdToCommentThreadMap = {};
   for (const comment of sortedComments) {
     // thread and append to it.
     if (comment.in_reply_to) {
       const thread = idThreadMap[comment.in_reply_to];
       if (thread) {
         thread.comments.push(comment);
         if (comment.id) idThreadMap[comment.id] = thread;
         continue;
       }
     }

     // Otherwise, this comment starts its own thread.
     if (!comment.path) {
       throw new Error('Comment missing required "path".');
     }
     const newThread: CommentThread = {
       comments: [comment],
       patchNum: comment.patch_set,
       commentSide: comment.side ?? CommentSide.REVISION,
       mergeParentNum: comment.parent,
       path: comment.path,
       line: comment.line,
       range: comment.range,
       rootId: comment.id,
     };
     if (!comment.line && !comment.range) {
       newThread.line = 'FILE';
     }
     threads.push(newThread);
     if (comment.id) idThreadMap[comment.id] = newThread;
   }
   return threads;
 }

 export interface CommentThread {
   /**
    * This can only contain at most one draft. And if so, then it is the last
    * comment in this list. This must not contain unsaved drafts.
    */
   comments: Array<CommentInfo | DraftInfo | RobotCommentInfo>;
   /**
    * Identical to the id of the first comment. If this is undefined, then the
    * thread only contains an unsaved draft.
    */
   rootId?: UrlEncodedCommentId;
   /**
    * Note that all location information is typically identical to that of the
    * first comment, but not for ported comments!
    */
   path: string;
   commentSide: CommentSide;
   /* mergeParentNum is the merge parent number only valid for merge commits
      when commentSide is PARENT.
      mergeParentNum is undefined for auto merge commits
      Same as `parent` in CommentInfo.
   */
   mergeParentNum?: number;
   patchNum?: RevisionPatchSetNum;
   /* Different from CommentInfo, which just keeps the line undefined for
      FILE comments. */
   line?: LineNumber;
   range?: CommentRange;
   /**
    * Was the thread ported over from its original location to a newer patchset?
    * If yes, then the location information above contains the ported location,
    * but the comments still have the original location set.
    */
   ported?: boolean;
   /**
    * Only relevant when ported:true. Means that no ported range could be
    * computed. `line` and `range` can be undefined then.
    */
   rangeInfoLost?: boolean;
 }

 export function equalLocation(t1?: CommentThread, t2?: CommentThread) {
   if (t1 === t2) return true;
   if (t1 === undefined || t2 === undefined) return false;
   return (
     t1.path === t2.path &&
     t1.patchNum === t2.patchNum &&
     t1.commentSide === t2.commentSide &&
     t1.line === t2.line &&
     t1.range?.start_line === t2.range?.start_line &&
     t1.range?.start_character === t2.range?.start_character &&
     t1.range?.end_line === t2.range?.end_line &&
     t1.range?.end_character === t2.range?.end_character
   );
 }

 export function getLastComment(thread: CommentThread): CommentInfo | undefined {
   const len = thread.comments.length;
   return thread.comments[len - 1];
 }

 export function getLastPublishedComment(
   thread: CommentThread
 ): CommentInfo | undefined {
   const publishedComments = thread.comments.filter(c => !isDraftOrUnsaved(c));
   const len = publishedComments.length;
   return publishedComments[len - 1];
 }

 export function getFirstComment(
   thread: CommentThread
 ): CommentInfo | undefined {
   return thread.comments[0];
 }

 export function countComments(thread: CommentThread) {
   return thread.comments.length;
 }

 export function isPatchsetLevel(thread: CommentThread): boolean {
   return thread.path === SpecialFilePath.PATCHSET_LEVEL_COMMENTS;
 }

 export function isUnresolved(thread: CommentThread): boolean {
   return !isResolved(thread);
 }

 export function isResolved(thread: CommentThread): boolean {
   const lastUnresolved = getLastComment(thread)?.unresolved;
   return !lastUnresolved ?? false;
 }

 export function isDraftThread(thread: CommentThread): boolean {
   return isDraft(getLastComment(thread));
 }

 export function isMentionedThread(
   thread: CommentThread,
   account?: AccountInfo
 ) {
   if (!account?.email) return false;
   return getMentionedUsers(thread)
     .map(v => v.email)
     .includes(account.email);
 }

 export function isRobotThread(thread: CommentThread): boolean {
   return isRobot(getFirstComment(thread));
 }

 export function hasHumanReply(thread: CommentThread): boolean {
   return countComments(thread) > 1 && !isRobot(getLastComment(thread));
 }

 export function lastUpdated(thread: CommentThread): Date | undefined {
   // We don't want to re-sort comments when you save a draft reply, so
   // we stick to the timestampe of the last *published* comment.
   const lastUpdated =
     getLastPublishedComment(thread)?.updated ?? getLastComment(thread)?.updated;
   return lastUpdated !== undefined ? parseDate(lastUpdated) : undefined;
 }
 /**
  * Whether the given comment should be included in the base side of the
  * given patch range.
  */
 export function isInBaseOfPatchRange(
   comment: {
     patch_set?: PatchSetNum;
     side?: CommentSide;
     parent?: number;
   },
   range: PatchRange
 ) {
   // If the base of the patch range is a parent of a merge, and the comment
   // appears on a specific parent then only show the comment if the parent
   // index of the comment matches that of the range.
   if (comment.parent && comment.side === CommentSide.PARENT) {
     return (
       isMergeParent(range.basePatchNum) &&
       comment.parent === getParentIndex(range.basePatchNum)
     );
   }

   // If the base of the range is the parent of the patch:
   if (
     range.basePatchNum === PARENT &&
     comment.side === CommentSide.PARENT &&
     comment.patch_set === range.patchNum
   ) {
     return true;
   }
   // If the base of the range is not the parent of the patch:
   return (
     range.basePatchNum !== PARENT &&
     comment.side !== CommentSide.PARENT &&
     comment.patch_set === range.basePatchNum
   );
 }

 /**
  * Whether the given comment should be included in the revision side of the
  * given patch range.
  */
 export function isInRevisionOfPatchRange(
   comment: {
     patch_set?: PatchSetNum;
     side?: CommentSide;
   },
   range: PatchRange
 ) {
   return (
     comment.side !== CommentSide.PARENT && comment.patch_set === range.patchNum
   );
 }

 /**
  * Whether the given comment should be included in the given patch range.
  */
 export function isInPatchRange(
   comment: CommentBasics,
   range: PatchRange
 ): boolean {
   return (
     isInBaseOfPatchRange(comment, range) ||
     isInRevisionOfPatchRange(comment, range)
   );
 }

 export function getPatchRangeForCommentUrl(
   comment: Comment,
   latestPatchNum: RevisionPatchSetNum
 ) {
   if (!comment.patch_set) throw new Error('Missing comment.patch_set');

   // TODO(dhruvsri): Add handling for comment left on parents of merge commits
   if (comment.side === CommentSide.PARENT) {
     return {
       patchNum: comment.patch_set,
       basePatchNum: PARENT,
     };
   } else if (latestPatchNum === comment.patch_set) {
     return {
       patchNum: latestPatchNum,
       basePatchNum: PARENT,
     };
   } else {
     return {
       patchNum: latestPatchNum,
       basePatchNum: comment.patch_set as BasePatchSetNum,
     };
   }
 }

 export function computeDiffFromContext(
   context: ContextLine[],
   path: string,
   content_type?: string
 ) {
   // do not render more than 20 lines of context
   context = context.slice(0, 20);
   const diff: DiffInfo = {
     meta_a: {
       name: '',
       content_type: '',
       lines: 0,
       web_links: [],
     },
     meta_b: {
       name: path,
       content_type: content_type || '',
       lines: context.length + context?.[0].line_number,
       web_links: [],
     },
     change_type: 'MODIFIED',
     intraline_status: 'OK',
     diff_header: [],
     content: [
       {
         skip: context[0].line_number - 1,
       },
       {
         b: context.map(line => line.context_line),
       },
     ],
   };
   return diff;
 }

 export function getCommentAuthors(
   threads?: CommentThread[],
   user?: AccountDetailInfo
 ) {
   if (!threads || !user) return [];
   const ids = new Set();
   const authors: AccountInfo[] = [];
   threads.forEach(t =>
     t.comments.forEach(c => {
       if (isDraft(c) && !ids.has(user._account_id)) {
         ids.add(user._account_id);
         authors.push(user);
         return;
       }
       if (c.author && !ids.has(c.author._account_id)) {
         ids.add(c.author._account_id);
         authors.push(c.author);
       }
     })
   );
   return authors;
 }

 /**
  * Add path info to every comment as CommentInfo returned from server does not
  * have that.
  */
 export function addPath<T>(comments: {[path: string]: T[]} = {}): {
   [path: string]: Array<T & {path: string}>;
 } {
   const updatedComments: {[path: string]: Array<T & {path: string}>} = {};
   for (const filePath of Object.keys(comments)) {
     updatedComments[filePath] = (comments[filePath] || []).map(comment => {
       return {...comment, path: filePath};
     });
   }
   return updatedComments;
 }

 /**
  * Add __draft:true to all drafts returned from server so that they can be told
  * apart from published comments easily.
  */
 export function addDraftProp(
   draftsByPath: {[path: string]: CommentInfo[]} = {}
 ) {
   const updated: {[path: string]: DraftInfo[]} = {};
   for (const filePath of Object.keys(draftsByPath)) {
     updated[filePath] = (draftsByPath[filePath] ?? []).map(draft => {
       return {...draft, __draft: true};
     });
   }
   return updated;
 }

 export function reportingDetails(comment: CommentBasics) {
   return {
     id: comment?.id,
     message_length: comment?.message?.trim().length,
     in_reply_to: comment?.in_reply_to,
     unresolved: comment?.unresolved,
     path_length: comment?.path?.length,
     line: comment?.range?.start_line ?? comment?.line,
     unsaved: isUnsaved(comment),
   };
 }

 export const USER_SUGGESTION_START_PATTERN = '```suggestion\n';

 // This can either mean a user or a checks provided fix.
 // "Provided" means that the fix is sent along with the request
 // when previewing and applying the fix. This is in contrast to
 // robot comment fixes, which are stored in the backend, and they
 // are referenced by a unique `FixId`;
 export const PROVIDED_FIX_ID = 'provided_fix' as FixId;

 export function hasUserSuggestion(comment: Comment) {
   return comment.message?.includes(USER_SUGGESTION_START_PATTERN) ?? false;
 }

 export function getUserSuggestion(comment: Comment) {
   if (!comment.message) return;
   const start =
     comment.message.indexOf(USER_SUGGESTION_START_PATTERN) +
     USER_SUGGESTION_START_PATTERN.length;
   const end = comment.message.indexOf('\n```', start);
   return comment.message.substring(start, end);
 }

 export function getContentInCommentRange(
   fileContent: string,
   comment: Comment
 ) {
   const lines = fileContent.split('\n');
   if (comment.range) {
     const range = comment.range;
     return lines.slice(range.start_line - 1, range.end_line).join('\n');
   }
   return lines[comment.line! - 1];
 }

 export function createUserFixSuggestion(
   comment: Comment,
   line: string,
   replacement: string
 ): FixSuggestionInfo[] {
   const lastLine = line.split('\n').pop();
   return [
     {
       fix_id: PROVIDED_FIX_ID,
       description: 'User suggestion',
       replacements: [
         {
           path: comment.path!,
           range: {
             start_line: comment.range?.start_line ?? comment.line!,
             start_character: 0,
             end_line: comment.range?.end_line ?? comment.line!,
             end_character: lastLine!.length,
           },
           replacement,
         },
       ],
     },
   ];
 }

 function getMentionedUsers(thread: CommentThread) {
   return thread.comments.map(c => extractMentionedUsers(c.message)).flat();
 }

 export function getMentionedThreads(
   threads: CommentThread[],
   account: AccountInfo
 ) {
   if (!account.email) return [];
   return threads.filter(t =>
     getMentionedUsers(t)
       .map(v => v.email)
       .includes(account.email)
   );
 }

 export function findComment(
   comments: {
     [path: string]: (CommentInfo | DraftInfo)[];
   },
   commentId: UrlEncodedCommentId
 ) {
   if (!commentId) return undefined;
   let comment;
   for (const path of Object.keys(comments)) {
     comment = comment || comments[path].find(c => c.id === commentId);
   }
   return comment;
 }
	/**
	* @license
	* Copyright 2020 Google LLC
	* SPDX-License-Identifier: Apache-2.0
	*/
	import {
	CommentBasics,
	CommentInfo,
	PatchSetNum,
	RobotCommentInfo,
	Timestamp,
	UrlEncodedCommentId,
	CommentRange,
	PatchRange,
	PARENT,
	ContextLine,
	BasePatchSetNum,
	RevisionPatchSetNum,
	AccountInfo,
	AccountDetailInfo,
	ChangeMessageInfo,
	VotingRangeInfo,
	FixSuggestionInfo,
	FixId,
	PatchSetNumber,
	} from '../types/common';
	import {CommentSide, SpecialFilePath} from '../constants/constants';
	import {parseDate} from './date-util';
	import {CommentIdToCommentThreadMap} from '../elements/diff/gr-comment-api/gr-comment-api';
	import {isMergeParent, getParentIndex} from './patch-set-util';
	import {DiffInfo} from '../types/diff';
	import {LineNumber} from '../api/diff';
	import {FormattedReviewerUpdateInfo} from '../types/types';
	import {extractMentionedUsers} from './account-util';

	export interface DraftCommentProps {
	// This must be true for all drafts. Drafts received from the backend will be
	// modified immediately with __draft:true before allowing them to get into
	// the application state.
	__draft: boolean;
	}

	export interface UnsavedCommentProps {
	// This must be true for all unsaved comment drafts. An unsaved draft is
	// always just local to a comment component like <gr-comment> or
	// <gr-comment-thread>. Unsaved drafts will never appear in the application
	// state.
	__unsaved: boolean;
	}

	export type DraftInfo = CommentInfo & DraftCommentProps;

	export type UnsavedInfo = CommentBasics & UnsavedCommentProps;

	export type Comment = UnsavedInfo \| DraftInfo \| CommentInfo \| RobotCommentInfo;

	// TODO: Replace the CommentMap type with just an array of paths.
	export type CommentMap = {[path: string]: boolean};

	export function isRobot<T extends CommentBasics>(
	x: T \| DraftInfo \| RobotCommentInfo \| undefined
	): x is RobotCommentInfo {
	return !!x && !!(x as RobotCommentInfo).robot_id;
	}

	export function isDraft<T extends CommentBasics>(
	x: T \| DraftInfo \| undefined
	): x is DraftInfo {
	return !!x && !!(x as DraftInfo).__draft;
	}

	export function isUnsaved<T extends CommentBasics>(
	x: T \| UnsavedInfo \| undefined
	): x is UnsavedInfo {
	return !!x && !!(x as UnsavedInfo).__unsaved;
	}

	export function isDraftOrUnsaved<T extends CommentBasics>(
	x: T \| DraftInfo \| UnsavedInfo \| undefined
	): x is UnsavedInfo \| DraftInfo {
	return isDraft(x) \|\| isUnsaved(x);
	}

	interface SortableComment {
	updated: Timestamp;
	id: UrlEncodedCommentId;
	}

	export interface ChangeMessage extends ChangeMessageInfo {
	// TODO(TS): maybe should be an enum instead
	type: string;
	expanded: boolean;
	commentThreads: CommentThread[];
	}

	export function isFormattedReviewerUpdate(
	message: ChangeMessage
	): message is ChangeMessage & FormattedReviewerUpdateInfo {
	return message.type === 'REVIEWER_UPDATE';
	}

	export type LabelExtreme = {[labelName: string]: VotingRangeInfo};

	export const NEWLINE_PATTERN = /\n/g;

	export const PATCH_SET_PREFIX_PATTERN =
	/^(?:Uploaded\s)?[Pp]atch [Ss]et \d+:\s(.*)/;

	export function sortComments<T extends SortableComment>(comments: T[]): T[] {
	return comments.slice(0).sort((c1, c2) => {
	const d1 = isDraft(c1);
	const d2 = isDraft(c2);
	if (d1 !== d2) return d1 ? 1 : -1;

	const date1 = parseDate(c1.updated);
	const date2 = parseDate(c2.updated);
	const dateDiff = date1.valueOf() - date2.valueOf();
	if (dateDiff !== 0) return dateDiff;

	const id1 = c1.id;
	const id2 = c2.id;
	return id1.localeCompare(id2);
	});
	}

	export function createUnsavedComment(thread: CommentThread): UnsavedInfo {
	return {
	path: thread.path,
	patch_set: thread.patchNum,
	side: thread.commentSide ?? CommentSide.REVISION,
	line: typeof thread.line === 'number' ? thread.line : undefined,
	range: thread.range,
	parent: thread.mergeParentNum,
	message: '',
	unresolved: true,
	__unsaved: true,
	};
	}

	export function createPatchsetLevelUnsavedDraft(
	patchNum?: PatchSetNumber,
	message?: string,
	unresolved?: boolean
	): UnsavedInfo {
	return {
	patch_set: patchNum,
	message,
	unresolved,
	path: SpecialFilePath.PATCHSET_LEVEL_COMMENTS,
	__unsaved: true,
	};
	}

	export function createUnsavedReply(
	replyingTo: CommentInfo,
	message: string,
	unresolved: boolean
	): UnsavedInfo {
	return {
	path: replyingTo.path,
	patch_set: replyingTo.patch_set,
	side: replyingTo.side,
	line: replyingTo.line,
	range: replyingTo.range,
	parent: replyingTo.parent,
	in_reply_to: replyingTo.id,
	message,
	unresolved,
	__unsaved: true,
	};
	}

	export function createCommentThreads(comments: CommentInfo[]) {
	const sortedComments = sortComments(comments);
	const threads: CommentThread[] = [];
	const idThreadMap: CommentIdToCommentThreadMap = {};
	for (const comment of sortedComments) {
	// thread and append to it.
	if (comment.in_reply_to) {
	const thread = idThreadMap[comment.in_reply_to];
	if (thread) {
	thread.comments.push(comment);
	if (comment.id) idThreadMap[comment.id] = thread;
	continue;
	}
	}

	// Otherwise, this comment starts its own thread.
	if (!comment.path) {
	throw new Error('Comment missing required "path".');
	}
	const newThread: CommentThread = {
	comments: [comment],
	patchNum: comment.patch_set,
	commentSide: comment.side ?? CommentSide.REVISION,
	mergeParentNum: comment.parent,
	path: comment.path,
	line: comment.line,
	range: comment.range,
	rootId: comment.id,
	};
	if (!comment.line && !comment.range) {
	newThread.line = 'FILE';
	}
	threads.push(newThread);
	if (comment.id) idThreadMap[comment.id] = newThread;
	}
	return threads;
	}

	export interface CommentThread {
	/**
	* This can only contain at most one draft. And if so, then it is the last
	* comment in this list. This must not contain unsaved drafts.
	*/
	comments: Array<CommentInfo \| DraftInfo \| RobotCommentInfo>;
	/**
	* Identical to the id of the first comment. If this is undefined, then the
	* thread only contains an unsaved draft.
	*/
	rootId?: UrlEncodedCommentId;
	/**
	* Note that all location information is typically identical to that of the
	* first comment, but not for ported comments!
	*/
	path: string;
	commentSide: CommentSide;
	/* mergeParentNum is the merge parent number only valid for merge commits
	when commentSide is PARENT.
	mergeParentNum is undefined for auto merge commits
	Same as `parent` in CommentInfo.
	*/
	mergeParentNum?: number;
	patchNum?: RevisionPatchSetNum;
	/* Different from CommentInfo, which just keeps the line undefined for
	FILE comments. */
	line?: LineNumber;
	range?: CommentRange;
	/**
	* Was the thread ported over from its original location to a newer patchset?
	* If yes, then the location information above contains the ported location,
	* but the comments still have the original location set.
	*/
	ported?: boolean;
	/**
	* Only relevant when ported:true. Means that no ported range could be
	* computed. `line` and `range` can be undefined then.
	*/
	rangeInfoLost?: boolean;
	}

	export function equalLocation(t1?: CommentThread, t2?: CommentThread) {
	if (t1 === t2) return true;
	if (t1 === undefined \|\| t2 === undefined) return false;
	return (
	t1.path === t2.path &&
	t1.patchNum === t2.patchNum &&
	t1.commentSide === t2.commentSide &&
	t1.line === t2.line &&
	t1.range?.start_line === t2.range?.start_line &&
	t1.range?.start_character === t2.range?.start_character &&
	t1.range?.end_line === t2.range?.end_line &&
	t1.range?.end_character === t2.range?.end_character
	);
	}

	export function getLastComment(thread: CommentThread): CommentInfo \| undefined {
	const len = thread.comments.length;
	return thread.comments[len - 1];
	}

	export function getLastPublishedComment(
	thread: CommentThread
	): CommentInfo \| undefined {
	const publishedComments = thread.comments.filter(c => !isDraftOrUnsaved(c));
	const len = publishedComments.length;
	return publishedComments[len - 1];
	}

	export function getFirstComment(
	thread: CommentThread
	): CommentInfo \| undefined {
	return thread.comments[0];
	}

	export function countComments(thread: CommentThread) {
	return thread.comments.length;
	}

	export function isPatchsetLevel(thread: CommentThread): boolean {
	return thread.path === SpecialFilePath.PATCHSET_LEVEL_COMMENTS;
	}

	export function isUnresolved(thread: CommentThread): boolean {
	return !isResolved(thread);
	}

	export function isResolved(thread: CommentThread): boolean {
	const lastUnresolved = getLastComment(thread)?.unresolved;
	return !lastUnresolved ?? false;
	}

	export function isDraftThread(thread: CommentThread): boolean {
	return isDraft(getLastComment(thread));
	}

	export function isMentionedThread(
	thread: CommentThread,
	account?: AccountInfo
	) {
	if (!account?.email) return false;
	return getMentionedUsers(thread)
	.map(v => v.email)
	.includes(account.email);
	}

	export function isRobotThread(thread: CommentThread): boolean {
	return isRobot(getFirstComment(thread));
	}

	export function hasHumanReply(thread: CommentThread): boolean {
	return countComments(thread) > 1 && !isRobot(getLastComment(thread));
	}

	export function lastUpdated(thread: CommentThread): Date \| undefined {
	// We don't want to re-sort comments when you save a draft reply, so
	// we stick to the timestampe of the last published comment.
	const lastUpdated =
	getLastPublishedComment(thread)?.updated ?? getLastComment(thread)?.updated;
	return lastUpdated !== undefined ? parseDate(lastUpdated) : undefined;
	}
	/**
	* Whether the given comment should be included in the base side of the
	* given patch range.
	*/
	export function isInBaseOfPatchRange(
	comment: {
	patch_set?: PatchSetNum;
	side?: CommentSide;
	parent?: number;
	},
	range: PatchRange
	) {
	// If the base of the patch range is a parent of a merge, and the comment
	// appears on a specific parent then only show the comment if the parent
	// index of the comment matches that of the range.
	if (comment.parent && comment.side === CommentSide.PARENT) {
	return (
	isMergeParent(range.basePatchNum) &&
	comment.parent === getParentIndex(range.basePatchNum)
	);
	}

	// If the base of the range is the parent of the patch:
	if (
	range.basePatchNum === PARENT &&
	comment.side === CommentSide.PARENT &&
	comment.patch_set === range.patchNum
	) {
	return true;
	}
	// If the base of the range is not the parent of the patch:
	return (
	range.basePatchNum !== PARENT &&
	comment.side !== CommentSide.PARENT &&
	comment.patch_set === range.basePatchNum
	);
	}

	/**
	* Whether the given comment should be included in the revision side of the
	* given patch range.
	*/
	export function isInRevisionOfPatchRange(
	comment: {
	patch_set?: PatchSetNum;
	side?: CommentSide;
	},
	range: PatchRange
	) {
	return (
	comment.side !== CommentSide.PARENT && comment.patch_set === range.patchNum
	);
	}

	/**
	* Whether the given comment should be included in the given patch range.
	*/
	export function isInPatchRange(
	comment: CommentBasics,
	range: PatchRange
	): boolean {
	return (
	isInBaseOfPatchRange(comment, range) \|\|
	isInRevisionOfPatchRange(comment, range)
	);
	}

	export function getPatchRangeForCommentUrl(
	comment: Comment,
	latestPatchNum: RevisionPatchSetNum
	) {
	if (!comment.patch_set) throw new Error('Missing comment.patch_set');

	// TODO(dhruvsri): Add handling for comment left on parents of merge commits
	if (comment.side === CommentSide.PARENT) {
	return {
	patchNum: comment.patch_set,
	basePatchNum: PARENT,
	};
	} else if (latestPatchNum === comment.patch_set) {
	return {
	patchNum: latestPatchNum,
	basePatchNum: PARENT,
	};
	} else {
	return {
	patchNum: latestPatchNum,
	basePatchNum: comment.patch_set as BasePatchSetNum,
	};
	}
	}

	export function computeDiffFromContext(
	context: ContextLine[],
	path: string,
	content_type?: string
	) {
	// do not render more than 20 lines of context
	context = context.slice(0, 20);
	const diff: DiffInfo = {
	meta_a: {
	name: '',
	content_type: '',
	lines: 0,
	web_links: [],
	},
	meta_b: {
	name: path,
	content_type: content_type \|\| '',
	lines: context.length + context?.[0].line_number,
	web_links: [],
	},
	change_type: 'MODIFIED',
	intraline_status: 'OK',
	diff_header: [],
	content: [
	{
	skip: context[0].line_number - 1,
	},
	{
	b: context.map(line => line.context_line),
	},
	],
	};
	return diff;
	}

	export function getCommentAuthors(
	threads?: CommentThread[],
	user?: AccountDetailInfo
	) {
	if (!threads \|\| !user) return [];
	const ids = new Set();
	const authors: AccountInfo[] = [];
	threads.forEach(t =>
	t.comments.forEach(c => {
	if (isDraft(c) && !ids.has(user._account_id)) {
	ids.add(user._account_id);
	authors.push(user);
	return;
	}
	if (c.author && !ids.has(c.author._account_id)) {
	ids.add(c.author._account_id);
	authors.push(c.author);
	}
	})
	);
	return authors;
	}

	/**
	* Add path info to every comment as CommentInfo returned from server does not
	* have that.
	*/
	export function addPath<T>(comments: {[path: string]: T[]} = {}): {
	[path: string]: Array<T & {path: string}>;
	} {
	const updatedComments: {[path: string]: Array<T & {path: string}>} = {};
	for (const filePath of Object.keys(comments)) {
	updatedComments[filePath] = (comments[filePath] \|\| []).map(comment => {
	return {...comment, path: filePath};
	});
	}
	return updatedComments;
	}

	/**
	* Add __draft:true to all drafts returned from server so that they can be told
	* apart from published comments easily.
	*/
	export function addDraftProp(
	draftsByPath: {[path: string]: CommentInfo[]} = {}
	) {
	const updated: {[path: string]: DraftInfo[]} = {};
	for (const filePath of Object.keys(draftsByPath)) {
	updated[filePath] = (draftsByPath[filePath] ?? []).map(draft => {
	return {...draft, __draft: true};
	});
	}
	return updated;
	}

	export function reportingDetails(comment: CommentBasics) {
	return {
	id: comment?.id,
	message_length: comment?.message?.trim().length,
	in_reply_to: comment?.in_reply_to,
	unresolved: comment?.unresolved,
	path_length: comment?.path?.length,
	line: comment?.range?.start_line ?? comment?.line,
	unsaved: isUnsaved(comment),
	};
	}

	export const USER_SUGGESTION_START_PATTERN = '```suggestion\n';

	// This can either mean a user or a checks provided fix.
	// "Provided" means that the fix is sent along with the request
	// when previewing and applying the fix. This is in contrast to
	// robot comment fixes, which are stored in the backend, and they
	// are referenced by a unique `FixId`;
	export const PROVIDED_FIX_ID = 'provided_fix' as FixId;

	export function hasUserSuggestion(comment: Comment) {
	return comment.message?.includes(USER_SUGGESTION_START_PATTERN) ?? false;
	}

	export function getUserSuggestion(comment: Comment) {
	if (!comment.message) return;
	const start =
	comment.message.indexOf(USER_SUGGESTION_START_PATTERN) +
	USER_SUGGESTION_START_PATTERN.length;
	const end = comment.message.indexOf('\n```', start);
	return comment.message.substring(start, end);
	}

	export function getContentInCommentRange(
	fileContent: string,
	comment: Comment
	) {
	const lines = fileContent.split('\n');
	if (comment.range) {
	const range = comment.range;
	return lines.slice(range.start_line - 1, range.end_line).join('\n');
	}
	return lines[comment.line! - 1];
	}

	export function createUserFixSuggestion(
	comment: Comment,
	line: string,
	replacement: string
	): FixSuggestionInfo[] {
	const lastLine = line.split('\n').pop();
	return [
	{
	fix_id: PROVIDED_FIX_ID,
	description: 'User suggestion',
	replacements: [
	{
	path: comment.path!,
	range: {
	start_line: comment.range?.start_line ?? comment.line!,
	start_character: 0,
	end_line: comment.range?.end_line ?? comment.line!,
	end_character: lastLine!.length,
	},
	replacement,
	},
	],
	},
	];
	}

	function getMentionedUsers(thread: CommentThread) {
	return thread.comments.map(c => extractMentionedUsers(c.message)).flat();
	}

	export function getMentionedThreads(
	threads: CommentThread[],
	account: AccountInfo
	) {
	if (!account.email) return [];
	return threads.filter(t =>
	getMentionedUsers(t)
	.map(v => v.email)
	.includes(account.email)
	);
	}

	export function findComment(
	comments: {
	[path: string]: (CommentInfo \| DraftInfo)[];
	},
	commentId: UrlEncodedCommentId
	) {
	if (!commentId) return undefined;
	let comment;
	for (const path of Object.keys(comments)) {
	comment = comment \|\| comments[path].find(c => c.id === commentId);
	}
	return comment;
	}